Adsorption of a model protein, the GroEL chaperonin, on surfaces

Understanding and controlling protein adsorption on surfaces is fundamental to many biological processes ranging from cell adhesion to the fabrication of protein biochips. In general, proteins need to retain their 3D conformation to perform their intended functions. However, when they are presented with a solid surface, complex interactions ranging from weak non- covalent binding to strong covalent bonding may occur, which can potentially induce conformational changes within the adsorbed protein. To investigate the surface adsorption process and its effects on a model protein, the chaperonin GroEL, we have applied contact mode atomic force microscopy, in buffer solution to probe the interactions between single proteins and surfaces in real space. We will discuss the adsorption of GroEL molecules on planar surfaces ( mica, graphite and gold) and specifically tailored nanostructured surfaces, which present structural features on the size scale of individual biological molecules.